The invention relates generally to multiple storage apparatuses connected via networks, and also to a technique of creating a replica of not only data but also configuration information for a storage apparatus in another apparatus.
A conventional data replication technique in which a replica of data is created and the replica of data in a storage apparatus is maintained in another storage apparatus is well known. In this data replication technique where two volumes are designated in advance, the replica of the primary volume is maintained in the secondary volume, by reflecting data changes made in the primary volume in the secondary volume.
The data replication technique is mainly used for disaster recovery. For example, JP-A-2000-132343 discloses a data replication technique in which, if a disaster occurs at a primary site, activity is resumed using the data replica in the volumes in the secondary site, making it possible to continue business.
Also, a conventional technique in which a replica of configuration information relating to the configuration of one storage apparatus is created in another storage apparatus is also well known. For example, JP-A-2005-44199 discloses that a centralized management server can match configuration information for multiple storage apparatuses by requesting the storage apparatuses to make the same change in their configuration information, such as to the number of logical volumes or the capacity of logical volumes
However, with these conventional techniques, it has not been possible to perform data replication and match configuration information simultaneously.
In other words, the data replication techniques are based on the premise that a logical volume with the same capacity has already been created in each of two storage apparatuses before creating a replica of data in one storage apparatus in the other storage apparatus. A storage apparatus administrator needs to create a logical volume with the same capacity in each of the two storage apparatuses, and pair-up the two volumes before date replication. As stated above, conventional data replication techniques have a problem in that data replication can not be linked with changes in configuration information.
Also, when a centralized management server makes a request to multiple storage apparatuses to make the same change to their respective configuration information, a storage apparatus administrator needs to judge whether or not the configuration information can be changed, depending on the progress of data replication. For example, when deleting a logical volume in both storage apparatuses, if data replication in the secondary volume has not been completed, it is necessary to delay the deletion of the primary volume even though it can already be deleted. As explained above, the technique of a centralized management server matching configuration information has a problem in that it cannot be linked with data replication.
Therefore, a technique of creating a replica of both data and configuration information for one storage apparatus in another storage apparatus and maintaining the replica will make it possible for a storage apparatus administrator to easily manage the storage apparatuses.